MECHANO-ACTIVE SCAFFOLDS - Intelligent Scaffolds for Tissue Engineering and Regenerative Medicine - page 545

27.2.4 Sheet-Form PLCL Scaffold
A sheet-form PLCL scaffold with 80% porosity and pores ranging
from 300-500 μ m in size was fabricated for cartilage tissue engi-
neering using a gel-pressing method. 23 The surface topology and
cross-sectional images obtained by SEM reveal that the PLCL scaf-
folds have a homogeneously interconnected and open-pore struc-
turewithoutaskinlayer.Thesepropertieswillimprovecell-seeding
e ciency, cell ingrowth, and, eventually, cartilage regeneration. We
showed that tensile properties of sheet-form PLCL scaffolds can be
controlled by changing the initial monomer composition of PLCL.
Tensile tests show that scaffolds that are fabricated from PLCL-1
(50:50 in LA:CA) have a lower tensile modulus (0.31 MPa) and a
higherelongationatbreak(520%)thanscaffoldsthatarefabricated
fromPLCL-2(60:40inLA:CA),whichpossessamodulusof0.73MPa
and an elongation of 136%. Both PLCL films and scaffolds exhibit a
completely rubberlike elasticity and show almost complete recov-
ery (over 94%) up to the tensile strain before a break occurs. These
elasticpropertiessuggestthatthePLCLscaffoldsaresuitableforuse
in cartilage tissue engineering. Because the mechanical properties
of PLCL scaffolds can be controlled by changing the monomer con-
tent,thesematerialscanbeappliedinarangeofapplicationsrelated
to cartilage tissue engineering that depend on specific mechanical
properties for ingrowth and eventual cartilage regeneration. PLCL-
1 and PLCL-2 films have very high strains at break (1,100% and
800%, respectively), low stresses at break (6.7 MPa and 7.5 MPa,
respectively), and very low tensile moduli (0.015 MPa and 0.014
MPa, respectively).
27.3 Mechano-Active Tissue Engineering
27.3.1 Vascular Tissue Engineering
Blood vessels are dynamic tissues with high elasticity and strength
suited to withstand both the flow of blood and the associated pres-
sure. Blood vessel walls are comprised of three layers: the tunica
intima, the tunica media, and the tunica adventitia. The intima con-
sists of a single layer of endothelial cells (EC) that are in direct